U.S. Pat. No. 6,371,397 B1 discloses a device for restraining a vehicle occupant that has a seat belt retractor and an electric motor in one unit. The torque of the electric motor is transmitted through a gear unit to a winding shaft that is mounted in a rotatable manner in a retractor frame of the seat belt retractor. The torque of the electric motor is used primarily in a pre-crash situation to eliminate the slack from the seat belt and to cause the movement of the belted occupant from an out-of-position state towards the seat back. The torque generated by the electric motor can also be used to adjust the wear comfort of the seat belt during normal driving operation, to return the seat belt back to the park position, and to effect an additional belt force limitation.